Display device including opening having protruded portion and depressed portion

ABSTRACT

A display device includes a substrate including a plastic layer, a barrier layer, and a display area in which an image is displayed. The display device further includes a light-emitting diode disposed in the display area, a planarization layer, and a pixel definition layer. The planarization layer and the pixel definition layer overlap the light-emitting diode. The display device further includes a thin film encapsulation layer disposed on the pixel definition layer. The thin film encapsulation layer includes at least one inorganic layer. The display device further includes an opening disposed in the display area and penetrating the substrate. The opening includes a protruded portion and a depressed portion, and the barrier layer overlaps at least one of the pixel definition layer and the planarization layer at the protruded portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/223,958 filed Dec. 18, 2018, which claimspriority under 35 U.S.C. § 119 to Korean Patent Application No.10-2018-0013882 filed on Feb. 5, 2018, the disclosures of which areincorporated by reference herein in their entirety.

TECHNICAL FIELD

Exemplary embodiments of the present invention relate to a displaydevice and a manufacturing method thereof.

DISCUSSION OF THE RELATED ART

A light emitting diode is an element used in display devices in whichholes supplied from an anode and electrons supplied from a cathode arecombined in an organic emission layer to form excitons. Light is emittedwhile the excitons are stabilized.

Light emitting diodes provide several advantages such as a wide viewingangle, a fast response speed, a reduced thickness, and low powerconsumption. As a result, light emitting diodes are widely used invarious electronic devices such as televisions, computer monitors,mobile phones, etc.

A recent trend relating display devices used in mobile phones is anincrease in the size of the display area and a decrease in the size ofthe non-display area surrounding the display area. As a result, certainmodules, such as a camera sensor, that have previously been disposed inthe non-display area may instead be disposed in the display area.

SUMMARY

Exemplary embodiments of the present invention provide a display devicein which an opening into which a module such as a camera is inserted ispositioned in a display area, such that the display area is enlarged.Also, a display device in which penetration of external air or moisturethrough the opening is prevented or reduced is provided. Further, amanufacturing method of such a display device is provided.

A display device according to an exemplary embodiment of the presentinvention includes a substrate including a plastic layer, a barrierlayer, and a display area in which an image is displayed. The displaydevice further includes a light-emitting diode disposed in the displayarea, a planarization layer, and a pixel definition layer. Theplanarization layer and the pixel definition layer overlap thelight-emitting diode. The display device further includes a thin filmencapsulation layer disposed on the pixel definition layer. The thinfilm encapsulation layer includes at least one inorganic layer. Thedisplay device further includes an opening disposed in the display areaand penetrating the substrate. The opening includes a protruded portionand a depressed portion, and the barrier layer overlaps at least one ofthe pixel definition layer and the planarization layer at the protrudedportion.

In an exemplary embodiment, the light-emitting diode includes a pixelelectrode connected to a transistor, a common electrode overlapping thepixel electrode, and an emission layer disposed between the pixelelectrode and the common electrode. The emission layer is disposed atthe protruded portion.

In an exemplary embodiment, the emission layer disposed at the protrudedportion includes at least two organic materials that emit light ofdifferent colors from each other.

In an exemplary embodiment, the emission layer has a disconnected shapealong an external circumferential surface of the opening.

In an exemplary embodiment, the inorganic layer is disposed at anexternal circumferential surface of the opening.

In an exemplary embodiment, the inorganic layer includes at least twolayers.

In an exemplary embodiment, an ultraviolet (UV) transmittance of theplastic layer is lower than a UV transmittance of the barrier layer.

In an exemplary embodiment, the plastic layer and the barrier layer arealternately stacked at least twice, and the opening includes at leastone additional protruded portion.

In an exemplary embodiment, the protruded portion and the at least oneadditional protruded portion are differentiated by a protrusion degree.

In an exemplary embodiment, a protrusion degree of the protruded portionand the at least one additional protruded portion increases as adistance from the light-emitting diode increases.

According to an exemplary embodiment of the present invention, a displaydevice includes a substrate including a plastic layer, a barrier layer,and a display area in which an image is displayed. The display devicefurther includes a transistor disposed in the display area and includinga gate electrode, a source electrode, and a drain electrode. The displaydevice further includes a pixel electrode connected to the transistor,an emission layer overlapping the pixel electrode, and an openingdisposed in the display area and penetrating the substrate. The openingincludes a protruded portion and a depressed portion. The barrier layerdisposed in the protruded portion overlaps a metal auxiliary layerdisposed at a same layer as at least one of the gate electrode, thesource electrode, and the pixel electrode.

In an exemplary embodiment, the display device further includes a bufferlayer disposed between the substrate and the gate electrode, asemiconductor layer disposed on the buffer layer, and a gate insulatinglayer disposed between the semiconductor layer and the gate electrode.

In an exemplary embodiment, at least one of the buffer layer and thegate insulating layer overlaps the metal auxiliary layer.

According to an exemplary embodiment of the present invention, a methodof manufacturing a display device includes forming a pixel electrodeconnected to a transistor, a planarization layer, and a pixel definitionlayer on a substrate. The substrate includes a plastic layer and abarrier layer, and the planarization layer and the pixel definitionlayer overlap the pixel electrode. The method further includes formingan opening penetrating the substrate and at least one of the pixeldefinition layer and the planarization layer. An externalcircumferential surface of the opening includes a protruded portion atwhich the barrier layer is protruded toward a center of the opening, anda depressed portion at which the plastic layer is recessed away from thecenter of the opening. The barrier layer overlaps at least one of thepixel definition layer and the planarization layer at the protrudedportion.

In an exemplary embodiment, the opening is formed using a laser havingan ultraviolet (UV) wavelength.

In an exemplary embodiment, a UV transmittance of the plastic layer islower than a UV transmittance of the barrier layer.

In an exemplary embodiment, the method further includes forming anemission layer on the pixel definition layer. The protruded portion andthe emission layer are overlapped.

In an exemplary embodiment, the method further includes forming a thinfilm encapsulation layer on the emission layer. The thin filmencapsulation layer includes at least one inorganic layer, and the atleast one inorganic layer is disposed on the external circumferentialsurface of the opening.

In an exemplary embodiment, the plastic layer and the barrier layer arealternately stacked.

In an exemplary embodiment, the external circumferential surface of theopening includes at least one additional protruded portion.

According to an exemplary embodiment of the present invention, a displaydevice includes a substrate including a plastic layer and a barrierlayer, a pixel electrode disposed on the substrate, a planarizationlayer disposed on the substrate, and a pixel definition layer disposedon the substrate. The planarization layer and the pixel definition layeroverlap the pixel electrode. The display device further includes anopening penetrating the substrate and at least one of the pixeldefinition layer and the planarization layer. The opening includes aprotruded portion disposed on an external circumferential surface of theopening, and a depressed portion formed on the external circumferentialsurface. The barrier layer overlaps at least one of the pixel definitionlayer and the planarization layer at the protruded portion.

In an exemplary embodiment, the protruded portion protrudes in adirection toward a center of the opening, and the depressed portion isrecessed in a direction away from the center of the opening.

In an exemplary embodiment, the barrier layer is protruded toward thecenter of the opening at the protruded portion, and the plastic layer isrecessed away from the center of the opening at the depressed portion.

In an exemplary embodiment, the display device further includes anemission layer disposed on the pixel definition layer. The emissionlayer is disconnected along the external circumferential surface of theopening.

According to exemplary embodiments of the present invention, a displaydevice in which the area of the display area is increased is provided.Also, a display device in which penetration of outside air or moisturethrough the opening is prevented or reduced is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention will become moreapparent by describing in detail exemplary embodiments thereof withreference to the accompanying drawings, in which:

FIG. 1A is a schematic view of a conventional display device.

FIG. 1B is a schematic view of a display device according to anexemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view of a region disposed adjacent to anopening in which a module is inserted according to an exemplaryembodiment of the present invention.

FIG. 3 is a cross-sectional view of one pixel according to an exemplaryembodiment of the present invention.

FIG. 4 is a cross-sectional view of a region disposed adjacent to anopening in which a module is inserted according to an exemplaryembodiment of the present invention.

FIG. 5 is a cross-sectional view of one pixel according to the exemplaryembodiment of FIG. 4 .

FIG. 6 is a cross-sectional view of a region disposed adjacent to anopening in which a module is inserted according to an exemplaryembodiment of the present invention.

FIG. 7 is a cross-sectional view of a region disposed adjacent to anopening in which a module is inserted according to an exemplaryembodiment of the present invention.

FIGS. 8 to 10 are cross-sectional views of a manufacturing method of adisplay device according to an exemplary embodiment of the presentinvention.

FIG. 11 is a view showing a plan image of an opening according to anexemplary embodiment of the present invention.

FIG. 12 is a view showing a plan image of an opening according to acomparative example.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention will be described morefully hereinafter with reference to the accompanying drawings. Likereference numerals may refer to like elements throughout theaccompanying drawings.

It will be understood that when an element such as a layer, film,region, or substrate is referred to as being “on” another element, itcan be directly on the other element or intervening elements may also bepresent. It will also be understood that when an element is referred toas being “between” two elements, it can be the only element between thetwo elements, or one or more intervening elements may also be present.It will also be understood that when an element is referred to as“overlapping” another element, it can be the only element overlappingthe other element, or one or more intervening elements may also beoverlapping the other element.

Spatially relative terms, such as “beneath”, “below”, “lower”, “under”,“above”, “upper”, etc., may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” or“under” other elements or features would then be oriented “above” theother elements or features. Thus, the exemplary terms “below” and“under” can encompass both an orientation of above and below.

FIG. 1A is a schematic view of a conventional display device. FIG. 1B isa schematic view of a display device according to an exemplaryembodiment of the present invention.

Referring to FIG. 1A, a conventional display device includes a displayarea DA in which an image is displayed, and a non-display area PA (alsoreferred to as a peripheral area) enclosing the display area DA in whichan image is not displayed. A module such as, for example, a camera C anda sensor S, is positioned in the non-display area PA.

Referring to FIG. 1B, in a display device according to an exemplaryembodiment, most of a front side of the display device is the displayarea DA. For example, unlike the display device of FIG. 1A, the displayarea DA of the display device in FIG. 1B extends to a periphery of thefront side of the display device. In the display device according to anexemplary embodiment, most of one surface of the display device isprovided as the display area DA, and a relatively small part of theperiphery of the display area DA is provided as the non-display area PA.

The display device according to an exemplary embodiment may include amodule such as, for example, a camera C and a sensor S, positioned inthe display area DA. For example, the module such as the camera C andthe sensor S may be positioned in the display area DA in which the imageis displayed.

Next, one pixel positioned in the display area, and an opening OPdisposed adjacent to the one pixel and in which the module (e.g., thecamera C, the sensor S, etc.) is inserted, are described with referenceto FIG. 2 and FIG. 3 .

FIG. 2 is a cross-sectional view of a region disposed adjacent to anopening in which a module is inserted according to an exemplaryembodiment of the present invention. FIG. 3 is a cross-sectional view ofone pixel according to an exemplary embodiment (e.g., the exemplaryembodiment of FIG. 2 ). Both the cross-sectional view of FIG. 2 and thecross-sectional view of FIG. 3 correspond to the display area DA.

Hereinafter, a region in which a stacking structure member SA includingconstituent elements positioned between a substrate 110 and a pixeldefinition layer 360 described later is partially removed in the displayarea DA in which the opening OP is disposed is referred to as an openingadjacent region AA.

In an exemplary embodiment, a diameter of an opening adjacent region AAis larger than a diameter of the opening OP. For example, in anexemplary embodiment, the diameter of the opening OP may be betweenabout 1 mm and about 4 mm, and the diameter of the opening adjacentregion AA may be the opening OP diameter±about 200 μm.

Referring to FIG. 2 , a substrate 110 according to an exemplaryembodiment may be, for example, a transparent insulation substrateincluding a polymer. The substrate 110 may be a flexible substrate.

In an exemplary embodiment, the substrate 110 includes a first plasticlayer 110 a, a first barrier layer 110 b, a second plastic layer 110 c,and a second barrier layer 110 d. In the exemplary embodiment shown inFIG. 2 , the substrate includes the plastic layer and the barrier layerthat are alternately stacked two times. However, exemplary embodimentsof the present invention are not limited thereto. For example, accordingto exemplary embodiments, a structure in which the plastic layer and thebarrier layer are alternately stacked once, or a structure in which theplastic layer and the barrier layer are alternately stacked three timesor more, may be included.

The first plastic layer 110 a and the second plastic layer 110 c mayinclude, for example, polyimide, polyethylene naphthalate, polyethyleneterephthalate (PET), polyarylate, polycarbonate, polyether Imide (PEI),polyethersulfone, etc.

The first plastic layer 110 a and the second plastic layer 110 c mayallow moisture and oxygen to more easily permeate the display devicecompared to a glass substrate. To compensate for this, in an exemplaryembodiment, the first barrier layer 110 b is positioned on the firstplastic layer 110 a, and the second barrier layer 110 d is positioned onthe second plastic layer 110 c.

The first barrier layer 110 b and the second barrier layer 110 d mayinclude an inorganic material such as, for example, a metal oxide, asilicon nitride, a silicon oxide, etc. For example, the first barrierlayer 110 b and the second barrier layer 110 d may include an inorganicmaterial such as AlO₃, SiO_(x), SiN_(x), etc. Each of the first barrierlayer 110 b and the second barrier layer 110 d may be a single layer ora multi-layer.

According to exemplary embodiments, the stacking structure member SAincluding the constituent elements positioned between the substrate 110and the pixel definition layer 360 is not positioned in the openingadjacent region AA. According to exemplary embodiments, the stackingstructure member SA includes a buffer layer 111, a transistor Tr, apixel electrode 191, etc., as described in detail with reference to FIG.3 .

Referring again to FIG. 2 , in an exemplary embodiment, the opening OPpenetrates the substrate 110, the pixel definition layer 360, anemission layer 370, and a common electrode 270. A module such as, forexample, the camera C or the sensor S described above may be inserted inthe opening OP. For example, in exemplary embodiments, the opening OPfully penetrates the substrate 110, the pixel definition layer 360, theemission layer 370, and the common electrode 270. In exemplaryembodiments, the opening OP penetrates the substrate 110 and at leastone of the pixel definition layer 360 and a planarization layer 180 (seeFIG. 3 ).

In an exemplary embodiment, an external circumferential surface of theopening OP includes protrusions and depressions. The externalcircumferential surface of the opening OP refers to the exposed surfaceof the opening OP within the opening OP. For example, in an exemplaryembodiment, the pixel definition layer 360 and the barrier layers 110 band 110 d include protruded portions A1 and A2 having a structure thatis convex toward the inside (or center) of the opening OP. In anexemplary embodiment, the external circumferential surface of theopening OP includes depressed portions B1 and B2 in which the plasticlayers 110 a and 110 c are formed to be concave compared to the barrierlayers 110 b and 110 d. In exemplary embodiments, the barrier layers 110b and 110 d overlap at least one of the pixel definition layer 360 andthe planarization layer 180 (see FIG. 3 ) at the protruded portions A1and A2.

In an exemplary embodiment, the depressed portion B1 included in thesecond plastic layer 110 c has a shape that is over-etched compared tothe depressed portion B2 of the first plastic layer 110 a. In anexemplary embodiment, a size of the depressed portion B1 included in thesecond plastic layer 110 c may be larger than the size of the depressedportion B2 included in the first plastic layer 110 a.

Also, in an exemplary embodiment, the protruded portion A1 included inthe second barrier layer 110 d has a shape that is over-etched comparedto the protruded portion A2 included in the first barrier layer 110 b.For example, as shown in FIG. 2 , the protruded portion A2 included inthe first barrier layer 110 b may have a shape that is protruded furthertoward the opening OP than the protruded portion A1 included in thesecond barrier layer 110 d. In an exemplary embodiment, protrudedportions may protrude more as the distance from the light emitting diodeincreases. For example, in an exemplary embodiment, a protrusion degreeof the protruded portions increases as the distance from the lightemitting diode increases. For example, protruded portions locatedfurther away from the light emitting diode protrude more toward thecenter of the opening (e.g., have an increased protrusion degree)compared to protruded portions located closer to the light emittingdiode. In an exemplary embodiment, the protruded portions and thedepressed portions are arranged repeatedly in a direction toward thesubstrate 110.

Referring to FIG. 2 , in an exemplary embodiment, the protruded portionsA1 and A2 and the depressed portions B1 and B2 are formed along theexternal circumferential surface of the opening OP. The protrudedportions A1 and A2 protrude toward the center of the opening OP, and thedepressed portions B1 and B2 are recessed away from the center of theopening OP. Thus, in an exemplary embodiment, the first barrier layer110 b and the second barrier layer 110 d respectively formed at thesecond protruded portion A2 and the first protruded portion A1 protrudetoward the center of the opening OP, and the first plastic layer 110 aand the second plastic layer 110 c respectively formed in the seconddepressed portion B2 and the first depressed portion B1 are recessedaway from the center of the opening OP.

In an exemplary embodiment, the protruded portions protrude more towardthe center of the opening OP in a direction toward the substrate 110.For example, in FIG. 2 , the second protruded portion A2 protrudestoward the center of the opening OP more than the first protrudedportion A1. For example, in an exemplary embodiment, the outermostsurface of the second protruded portion A2 is located closer to thecenter of the opening OP than the outermost surface of the firstprotruded portion A1. That is, in an exemplary embodiment, the distancebetween opposing outermost surfaces of the first protruded portion A1that face each other across the opening OP is greater than the distancebetween opposing outermost surfaces of the second protruded portion A2that face each other across the opening OP, as shown in FIG. 2 .

A laser used in a process that forms the opening OP may have a Gaussianshape. For example, the laser according to an exemplary embodiment mayhave a shape such that the width decreases closer to a lowest surface ofthe substrate 110. A protrusion degree of the plurality of protrudedportions may be differentiated according to these shapes. For example,the plurality of protruded portions may protrude more as the protrudedportions get closer to the lowest surface of the substrate 110. However,exemplary embodiments of the present invention are not limited thereto.For example, according to exemplary embodiments, the shape of theprotruded portions and the depressed portions may be changed when usinga laser of other shapes.

In an exemplary embodiment, on a plane, the size of the opening of thepixel definition layer 360 and the barrier layers 110 b and 110 d issmaller than the size of the opening of the plastic layers 110 a and 110c. An undercut may be formed between the barrier layers 110 b and 110 dand the plastic layers 110 a and 110 c. In exemplary embodiments, theboundary between the plastic layers 110 a and 110 c and the opening OPhas a shape that is separated from the center of the opening OP morethan the boundary between the barrier layers 110 b and 110 d and theopening OP. For example, in an exemplary embodiment, the distancebetween opposing portions of the plastic layers 110 a and 110 c thatface each other across the opening OP is greater than the distancebetween opposing portions of the barrier layers 110 b and 110 d thatface each other across the opening OP. For example, in an exemplaryembodiment, ends of the plastic layers 110 a and 110 c that face theopening OP are further from the opening than ends of the barrier layers110 b and 110 d that face the opening.

The barrier layers 110 b and 110 d and the plastic layers 110 a and 110c may have different ultraviolet (UV) wavelength transmittance from eachother. For example, the transmittance of the plastic layers 110 a and110 c for a UV wavelength may be lower than that of the barrier layers110 b and 110 d. For example, as the plastic layers 110 a and 110 cabsorb a greater amount of UV light, they may be etched more than thebarrier layers 110 b and 110 d. Accordingly, the depressed portions B1and B2 may be formed at the plastic layer 110 a and 110 c, and theprotruded portions A1 and A2 may be formed at the barrier layers 110 band 110 d.

In exemplary embodiments, the protruded portions A1 and A2 are formed inthe region in which the barrier layers 110 b and 110 d are positioned.Thus, in an exemplary embodiment, the substrate 110 includes at leasttwo barrier layers 110 b and 110 d, and the opening OP includes at leasttwo protruded portions A1 and A2 disposed in areas corresponding to theat least two barrier layers 110 b and 110 d.

In exemplary embodiments, the protruded portion A1 included in thesecond barrier layer 110 d overlaps the pixel definition layer 360. Thepixel definition layer 360 may prevent the end of the second barrierlayer 110 d that forms the protruded portion A1 from being damaged.

In exemplary embodiments, the protruded portion A1 overlaps the emissionlayer 370 positioned adjacent to the opening OP. In an exemplaryembodiment, the emission layer 370 may include an organic material, andmay include at least two organic materials emitting light of differentcolors from each other. In an exemplary embodiment, the organicmaterials positioned at the region forming the image and emitting lightof the different colors from each other may be stacked in a plurality oflayers at the protruded portion A1. For example, at least one of anorganic material emitting red light, an organic material emitting greenlight, and an organic material emitting blue light may be positioned.

In exemplary embodiments, the emission layer 370 has a disconnectedshape at the opening OP. For example, if the emission layer 370 had acontinuous shape extending along the protruded portions A1 and A2 andthe depressed portions B1 and B2 in the opening OP, outside air ormoisture may penetrate into the emission layer 370 through the openingOP. However, according to exemplary embodiments of the presentinvention, the protruded portions A1 and A2 and the depressed portionsB1 and B2 are stably formed. As a result, the emission layer 370 has adisconnected shape at the opening OP (e.g., at the protruded portion A1in the opening OP). For example, due to the protruded portions A1 and A2and the depressed portions B1 and B2 being stably formed, the emissionlayer 370 is not continuously formed along the external circumferentialsurface of the opening OP (e.g., the emission layer 370 has adisconnected shape along the external circumferential surface of theopening OP). As a result, outside air or moisture may be prevented frompenetrating through the emission layer 370.

According to exemplary embodiments, the emission layer 370 having adisconnected shape along the external circumferential surface of theopening OP refers to the emission layer 370 not being continuouslyformed and extending along the external circumferential surface of theopening OP.

Exemplary embodiments are described herein in which the protrudedportion A1, and the pixel definition layer 360 and the emission layer370, overlap. However, exemplary embodiments of the present inventionare not limited thereto. For example, according to exemplaryembodiments, a part of the constituent elements included in thelater-described stacking structure member SA may be positioned at theprotruded portion A1.

Referring to FIG. 3 , in an exemplary embodiment, a thin filmencapsulation layer 400 includes an inorganic layer 410 and an organiclayer 420. The inorganic layer 410 may include a first inorganic layer410 a and a second inorganic layer 410 b. In this case, at least one ofthe first inorganic layer 410 a and the second inorganic layer 410 b maybe positioned at the opening OP. According to an exemplary embodiment,both the first inorganic layer 410 a and the second inorganic layer 410b are positioned at the opening OP. The first inorganic layer 410 a andthe second inorganic layer 410 b may be represented as one layerincluding the same material.

In an exemplary embodiment, the inorganic layer 410 is positioned alongthe external circumferential surface of the opening OP. For example, theinorganic layer 410 may be positioned to enclose the entire externalcircumferential surface of the opening OP before the module is insertedinto the opening OP. For example, the inorganic layer 410 may cover theentire external circumferential surface of the opening OP. The inorganiclayer 410 may prevent outside air or moisture from penetrating throughthe opening OP.

Next, the stacking structure member SA and other constituent elementsaccording to exemplary embodiments of the present invention aredescribed in detail with reference to FIG. 3 .

According to exemplary embodiments, the buffer layer 111 may bepositioned on the above-described substrate 110, or the buffer layer 111may be omitted. The buffer layer 111 may include an inorganic materialsuch as, for example, a silicon oxide, a silicon nitride, etc. Thebuffer layer 111 may be a single layer or a multi-layer.

The buffer layer 111 may flatten one surface of the substrate 110 toplanarize it, and may prevent an impurity from being diffused into asemiconductor layer 154 of the display device, or prevent thepenetration of moisture into the display device, thus, preventing thedegradation of the characteristics of the semiconductor layer 154.

The semiconductor layer 154 of the transistor Tr is positioned on thebuffer layer 111. The semiconductor layer 154 includes a channel region152, and a source region 153 and a drain region 155 positioned atrespective sides of the channel region 152. The source region 153 andthe drain region 155 are doped. The semiconductor layer 154 may include,for example, polysilicon, amorphous silicon, or an oxide semiconductor.

A light blocking electrode may be positioned between the substrate 110and the semiconductor layer 154. The light blocking electrode preventsexternal light from reaching the semiconductor layer 154, therebypreventing deterioration of characteristics of the semiconductor layer154 and reducing a leakage current of the transistor Tr.

A gate insulating layer 141 is positioned on the semiconductor layer154. The gate insulating layer 141 may overlap the front surface of thesubstrate 110. The gate insulating layer 141 may include an inorganicinsulating material such as, for example, a silicon oxide (SiOx), asilicon nitride (SiNx), etc.

A gate conductor including a gate electrode 124 of the transistor Tr ispositioned on the gate insulating layer 141. The gate electrode 124 mayoverlap the channel region 152 of the semiconductor layer 154.

The gate conductor may include a metal such as, for example, molybdenum(Mo), copper (Cu), aluminum (Al), silver (Ag), chromium (Cr), tantalum(Ta), titanium (Ti), etc., or a metal alloy thereof. The gate conductormay be a single layer or a multi-layer.

An interlayer insulating layer 160 including the inorganic insulatingmaterial or the organic insulating material is positioned on the gateelectrode 124.

A data conductor including a source electrode 173 and a drain electrode175 of the transistor Tr, a data line, a driving voltage line, etc., ispositioned on the interlayer insulating layer 160. The source electrode173 and the drain electrode 175 may be respectively connected to thesource region 153 and the drain region 155 of the semiconductor layer154 through contact holes 63 and 65 formed in the interlayer insulatinglayer 160 and the gate insulating layer 141.

The data conductor may include a metal such as, for example, aluminum(Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt), palladium(Pd), nickel (Ni), molybdenum (Mo), tungsten (W), titanium (Ti),chromium (Cr), tantalum (Ta), etc., or a metal alloy thereof. The dataconductor may be a single layer or a multi-layer (e.g., Ti/Al/Ti,Mo/Al/Mo, Mo/Cu/Mo, etc.).

The gate electrode 124, the source electrode 173, and the drainelectrode 175 form the transistor Tr along with the semiconductor layer154. The transistor Tr may be, for example, a driving transistor in thepixel of the emissive display device. The transistor Tr may be referredto as a top-gate transistor, since the gate electrode 124 is positionedabove the semiconductor layer 154. However, the structure of thetransistor Tr is not limited thereto. For example, in exemplaryembodiments, the transistor Tr may be a bottom-gate transistor in whichthe gate electrode is positioned below the semiconductor layer 154.

A planarization layer 180 is positioned on the interlayer insulatinglayer 160 and the data conductor. The planarization layer 180 removesand planarizes a step to increase emission efficiency of the organiclight emitting element to be formed thereon. The planarization layer 180may cover the transistor Tr.

The planarization layer 180 may include, for example, an organicinsulating material. The organic insulating material may include, forexample, polyimide, polyamide, polyacrylate, polyphenylene ether,polyphenylene sulfide, unsaturated polyester, an epoxy resin, phenolresin, etc. However, the planarization layer 180 is not limited thereto.

The pixel electrode 191 is positioned on the planarization layer 180.The pixel electrode 191 is connected to the drain electrode 175 of thetransistor Tr through a contact hole 81 formed in the planarizationlayer 180.

The pixel electrode 191 may be formed of a reflective conductivematerial or a semi-transmissive conductive material, or may be formed ofa transparent conductive material. For example, the pixel electrode 191may include a transparent conductive material such as, for example,indium tin oxide (ITO) and indium zinc oxide (IZO), or a metal such as,for example, lithium (Li), calcium (Ca), aluminum (Al), silver (Ag),magnesium (Mg), and gold (Au).

The pixel definition layer 360 is positioned on the planarization layer180 and the pixel electrode 191. The pixel definition layer 360 has anopening 91 overlapping a part of the pixel electrode 191. The opening 91of the pixel definition layer 360 may limit the region corresponding tothe pixel.

As described above, in exemplary embodiments, the pixel definition layer360 overlaps the second barrier layer 110 d in the protruded portion A1included in the opening OP. A description of the pixel definition layer360 in the region adjacent to the opening OP is omitted herein.

The pixel definition layer 360 may include an organic insulatingmaterial such as, for example, polyimide, polyacrylate, and polyamide.

The emission layer 370 is positioned on the pixel electrode 191. Theemission layer 370 includes an emission region, and may additionallyinclude at least one of a hole injection region, a hole transportingregion, an electron injection region, and an electron transportingregion.

The emission layer 370 may be made of the organic material uniquelyemitting light of a primary color such as red, green, and blue, and mayhave a structure in which a plurality of organic materials emittinglight of different colors are stacked.

As described above, in exemplary embodiments, the emission layer 370 ispositioned at a region adjacent to the opening OP, and overlap theprotruded portion A1. For convenience of explanation, a repeateddescription thereof is omitted.

The common electrode 270, which transmits a common voltage, ispositioned on the emission layer 370. The common electrode 270 mayinclude a transparent conductive material such as, for example, indiumtin oxide (ITO) and indium zinc oxide (IZO). The common electrode 270may formed by thinly laminating metals such as, for example, calcium(Ca), barium (Ba), magnesium (Mg), aluminum (Al), and silver (Ag), tohave a light transmitting property. At least one protection layer orfunctional layer may be positioned on the common electrode 270.

The pixel electrode 191, the emission layer 370, and the commonelectrode 270 of each pixel form an organic light emitting diode (OLED)as the light emitting diode (LED). In an exemplary embodiment, the pixelelectrode 191 may be an anode of the hole injection electrode, and thecommon electrode 270 may be a cathode of the electron injectionelectrode. In contrast, in an exemplary embodiment, the pixel electrode191 may be the cathode and the common electrode 270 may be the anode.Holes and electrons are injected into the emission layer 370 from thepixel electrode 191 and the common electrode 270, respectively, andexitons generated by coupling the injected holes and electrons fall froman excited state to a ground state to emit light.

In exemplary embodiments, the thin film encapsulation layer 400 ispositioned on the common electrode 270. The thin film encapsulationlayer 400 may include a plurality of inorganic layers, and may include astructure in which an inorganic layer and an organic layer arealternately stacked. The thin film encapsulation layer 400 according toan exemplary embodiment includes the inorganic layer 410 and the organiclayer 420. For example, the first inorganic layer 410 a, the organiclayer 420, and the second inorganic layer 410 b that are sequentiallystacked may be included in the thin film encapsulation layer 400. Thethin film encapsulation layer 400 may include at least one sandwichstructure in which at least one organic layer 420 is inserted between atleast two inorganic layers 410 a and 410 b. However, the thin filmencapsulation layer 400 is not limited thereto, and various otherstacking structures may be implemented. The uppermost layer of the thinfilm encapsulation layer 400 (e.g., the layer exposed to the outside)may be the inorganic layer. As a result, moisture may be prevented frompenetrating the light-emitting diode.

The inorganic layer 410 may include, for example, a metal oxide or ametal nitride. For example, the inorganic layer 410 may include any oneof SiNx, Al₂O₃, SiO₂, and TiO₂.

The organic layer 420 may include a polymer. For example, the organiclayer 420 may be formed by any one of polyethylene terephthalate,polyimide, polycarbonate, epoxy, polyethylene, and polyacrylate.

In the exemplary embodiments described herein, the thin filmencapsulation layer 400 is positioned directly on the common electrode270. However, exemplary embodiments of the present invention are notlimited thereto. For example, in exemplary embodiments, a separatefiller or adhesive may be positioned between the common electrode 270and the thin film encapsulation layer 400.

Next, a display device according to an exemplary embodiment of thepresent invention will be described with reference to FIGS. 4 to 7 .

FIG. 4 is a cross-sectional view of a region disposed adjacent to anopening in which a module is inserted according to an exemplaryembodiment of the present invention. FIG. 5 is a cross-sectional view ofone pixel according to the exemplary embodiment of FIG. 4 . FIG. 6 is across-sectional view of a region disposed adjacent to an opening inwhich a module is inserted according to an exemplary embodiment of thepresent invention. FIG. 7 is a cross-sectional view of a region disposedadjacent to an opening in which a module is inserted according to anexemplary embodiment of the present invention.

For convenience of explanation, a further description of elements andprocesses previously described with reference to FIGS. 2 and 3 may beomitted herein.

First, referring to FIGS. 4 and 5 , in an exemplary embodiment, in theopening adjacent region AA in which the opening OP is positioned, theplanarization layer 180 is positioned on the second barrier layer 110 d.As shown in FIG. 5 , in an exemplary embodiment, the planarization layer180 has a shape that extends from the region overlapping the organiclight emitting diode OLED to the region in which the opening OP ispositioned. However, exemplary embodiments of the present invention arenot limited thereto. For example, in exemplary embodiments, theplanarization layer 180 has a shape that is separated at the region inwhich the organic light emitting diode OLED is positioned and the regionin which the opening OP is positioned.

In exemplary embodiments, the planarization layer 180 includes theorganic material. For example, the planarization layer 180 may includeat least one of polyimide, polyamide, polyacrylate, polyphenylene ether,polyphenylene sulfide, unsaturated polyester, epoxy resin, and phenolresin. However, the planarization layer 180 is not limited thereto.

The planarization layer 180 overlapping the protruded portion A1 mayprotect the end of the second barrier layer 110 d during themanufacturing process. In exemplary embodiments, the end of the secondbarrier layer 110 d has a shape protruded toward the center of theopening OP while overlapping the planarization layer 180.

Next, referring to FIG. 6 , in an exemplary embodiment, in the openingadjacent region AA, the buffer layer 111 and the gate insulating layer141 are positioned on the second barrier layer 110 d. Similar to asdescribed above, the buffer layer 111 and the gate insulating layer 141positioned in the region in which the pixel is positioned may have ashape that extends to the opening adjacent region AA in which the moduleis inserted.

In exemplary embodiments, a metal auxiliary layer 129 is positioned onthe gate insulating layer 141 at the protruded portion A1. The metalauxiliary layer 129 may be positioned at the same layer as the gateconductor including the gate electrode 124. According to an exemplaryembodiment, the metal auxiliary layer 129 may include the same materialas the gate conductor, and may be formed in the same process.

In exemplary embodiments, the metal auxiliary layer 129 overlaps thesecond barrier layer 110 d. The metal auxiliary layer 129 overlappingthe second barrier layer 110 d may prevent the end of the second barrierlayer 110 d from being damaged in the process of forming the opening OP.In addition, in exemplary embodiments, the undercut described above isstably formed between the second barrier layer 110 d and the secondplastic layer 110 c, which may aid in preventing the end of the secondbarrier layer 110 d from being damaged in the process of forming theopening OP.

In exemplary embodiments, edges of the metal auxiliary layer 129, thegate insulating layer 141, the buffer layer 111, and the second barrierlayer 110 d may be substantially aligned with one another.

In exemplary embodiments, at least one of the buffer layer 111 and thegate insulating layer 141 overlaps the metal auxiliary layer 129.

In exemplary embodiments, the metal auxiliary layer 129 is disposed atthe same layer as at least one of the gate electrode 124, the sourceelectrode 173, and the pixel electrode 191.

As shown in FIG. 6 , in an exemplary embodiment, the emission layer 370is positioned between the pixel definition layer 360 and the commonelectrode 270. Also, in an exemplary embodiment, a part 379 of theemission layer 370 may also be positioned at the end of the firstbarrier layer 110 b. For example, in the process of forming the emissionlayer 370, the organic material forming the emission layer 370 may alsobe positioned on the opening OP. In this case, the part of the organicmaterial may be positioned on the first barrier layer 110 b protrudedtoward the center of the opening OP, thus, resulting in the part 379 ofthe emission layer 370 remaining at the end of the first barrier layer110 b.

According to an exemplary embodiment, even if the organic materialforming the emission layer 370 is positioned on the opening OP (e.g.,even if part 379 remains), the organic material positioned on the firstbarrier layer 110 b and the organic material positioned on the secondbarrier layer 110 d have the separated or disconnected shape.Accordingly, outside air or moisture may be prevented from penetratingthrough the elongated emission layer 370. For example, even if outsideair or moisture penetrates through the small part 379 of the emissionlayer 370 positioned on the first barrier layer 110 b, the elongatedportion of the emission layer 370 positioned on the second barrier layer110 d is not affected due to the separated or disconnected shape.

Next, referring to FIG. 7 , in an exemplary embodiment, in the openingadjacent region AA in which the opening OP is positioned, a metalauxiliary layer 179 is positioned on the second barrier layer 110 d. Anexemplary embodiment in which the metal auxiliary layer 179 ispositioned directly on the second barrier layer 110 d is shown in FIG. 7. However, exemplary embodiments of the present invention are notlimited thereto. For example, in exemplary embodiments, at least one ofthe buffer layer 111 and the gate insulating layer 141 may be positionedbetween the second barrier layer 110 d and the metal auxiliary layer179.

In exemplary embodiments, the metal auxiliary layer 179 includes thesame material as the data conductor or the same material as the pixelelectrode 191. When the metal auxiliary layer 179 includes the samematerial as the data conductor, it may be formed in the same process asthe manufacturing process of the data conductor. When the metalauxiliary layer 179 includes the same material as the pixel electrode191, it may be formed in the same process as the manufacturing processof the pixel electrode 191.

Next, a manufacturing method of a display device according to anexemplary embodiment of the present invention will be described withreference to FIGS. 8 to 10 .

FIGS. 8 to 10 are cross-sectional views of a manufacturing method of adisplay device according to an exemplary embodiment of the presentinvention.

For convenience of explanation, a further description of elements andprocesses previously described may be omitted herein.

Referring to FIG. 8 , the substrate 110 including the first plasticlayer 110 a, the first barrier layer 110 b, the second plastic layer 110c, and the second barrier layer 110 d is prepared. According to anexemplary embodiment, a carrier glass may be positioned at a rearsurface of the substrate 110.

The stacking structure member SA including the transistor Tr and thepixel electrode 191 connected to the transistor Tr is formed on thesubstrate 110. The stacking structure member SA is not positioned in theregion in which the opening OP is formed later. Then, the pixeldefinition layer 360 is formed to overlap the front side of thesubstrate 110.

Next, as shown in FIG. 9 , the opening OP penetrating the pixeldefinition layer 360 and the substrate 110 is formed. The opening OP maybe formed by a variety of methods. For example, in exemplaryembodiments, a wet etching process, a dry etching process, a laseretching process, etc. may be used. For example, a laser etching processhaving a UV wavelength may be used.

In this case, the transmittance of the first plastic layer 110 a and thesecond plastic layer 110 c for a UV wavelength may be lower than thetransmittance of the first barrier layer 110 b and the second barrierlayer 110 d. The laser having a UV wavelength may over-etch the firstplastic layer 110 a and the second plastic layer 110 c compared to thefirst barrier layer 110 b and the second barrier layer 110 d. Theundercut may be positioned between the second barrier layer 110 d andthe second plastic layer 110 c and between the first barrier layer 110 band the first plastic layer 110 a.

Also, when using a predetermined laser, the etching degree of the secondplastic layer 110 c may be larger than the etching degree of the firstplastic layer 110 a. Similarly, the etching degree of the second barrierlayer 110 d may be larger than the etching degree of the first barrierlayer 110 b. Accordingly, the first plastic layer 110 a may bepositioned to be closer to the center of the opening OP compared to thesecond plastic layer 110 c, and the first barrier layer 110 b may alsobe positioned to be closer to the center of the opening OP compared tothe second barrier layer 110 d. The first plastic layer 110 a and thefirst barrier layer 110 b may have the protruded shape compared to thesecond plastic layer 110 c and the second barrier layer 110 d.

In exemplary embodiments, the opening OP has the protruded portion A atthe region in which the first barrier layer 110 b and the second barrierlayer 110 d are protruded, and has the depressed portion B at the regionin which the over-etched first plastic layer 110 a and second plasticlayer 110 c are positioned.

In exemplary embodiments, the protruded portion A in which the secondbarrier layer 110 d is positioned overlaps the pixel definition layer360. This results in a more stably formed protruded shape, as well asthe prevention against damage that may occur due to the etching process.For example, when there is no overlapping, the end of the protrudedsecond barrier layer 110 d may be damaged by the laser used in theetching process. Thus, in exemplary embodiments, the end of the secondbarrier layer 110 d overlaps the pixel definition layer 360, resultingin the prevention of damage that may occur due to the etching process,and resulting in a more stably formed protruded shape.

Next, as shown in FIG. 10 , in exemplary embodiments, the emission layer370 is formed on the pixel definition layer 360. Since the opening OPincludes the protruded portion A and the depressed portion B, theemission layer 370 is not connected along the opening OP. For example,the emission layer 370 has a disconnected shape at the protruded portionA. For example, due to the inclusion of the protruded portion A and thedepressed portion B, the emission layer 370 is not continuously formedalong the external circumferential surface of the opening OP.

The emission layer 370 includes an organic material. Moisture maypenetrate the emission layer 370 positioned adjacent to the opening OP.As a result, if the emission layer 370 has a continuous shape instead ofa disconnected shape, the emission layer 370 forming the pixel may bedamaged.

According to exemplary embodiments of the present invention, since thesubstrate 110 includes the stably formed protruded portion A anddepressed portion B, the emission layer 370 including the organicmaterial is not continuous, but rather, has a disconnected shape at theopening OP. As a result, moisture may be prevented from penetrating thelight-emitting diode, thereby improving reliability.

According to exemplary embodiments, a part of the organic materialforming the emission layer 370 may also be positioned at the end of thefirst barrier layer 110 b in the process of forming the emission layer370.

Next, the common electrode 270 is formed on the emission layer 370 andthe thin film encapsulation layer 400 is formed, thereby providing thedisplay device as shown, for example, in FIGS. 2 and 3 .

The thin film encapsulation layer 400 according to an exemplaryembodiment of the present invention may include the first inorganiclayer 410 a, the organic layer 420, and the second inorganic layer 410b. The organic layer 420 may be formed by a printing process accordingto an exemplary embodiment. The organic layer 420 is not positioned inthe region adjacent to the opening OP according to an exemplaryembodiment.

The inorganic layer 410 positioned at the opening OP may also include atleast one of the first inorganic layer 410 a and the second inorganiclayer 410 b. The inorganic layer 410 may include both of the firstinorganic layer 410 a and the second inorganic layer 410 b. In exemplaryembodiments in which first inorganic layer 410 a and the secondinorganic layer 410 b include the same material, the layers are notdivided into separate layers.

For convenience of explanation, only the manufacturing method for theexemplary embodiment of FIGS. 2 and 3 is described in detail herein.However, it is to be understood that the display device according toexemplary embodiments other than the exemplary embodiment of FIGS. 2 and3 may also be manufactured through a similar method.

Next, the opening according to an exemplary embodiment of the presentinvention and a comparative example is described with reference to FIGS.11 and 12 .

FIG. 11 is a view showing a plan image of an opening according to anexemplary embodiment of the present invention. FIG. 12 is a view showinga plan image of an opening according to a comparative example.

Referring to FIG. 11 , it can be seen that in an exemplary embodiment,the protruded portion is uniformly formed in the region adjacent to theopening. However, referring to FIG. 12 , it can be seen that theinorganic layer is non-uniformly damaged such that the protruded portionis not stably formed.

When the protruded portion is not stably formed, the emission layer maybe continuously formed along the external circumferential surface of theopening. As a result, outside air or moisture may penetrate through theemission layer positioned at the opening (e.g., exposed through theopening). The penetrating outside air or moisture may move along theemission layer, thereby damaging the emission layer positioned at thepixel area and lowering the display quality.

The display device according to exemplary embodiments of the presentinvention includes the opening, which includes the protruded portion anddepressed portion stably formed thereon. The protruded portion is formedto have the protruded shape described herein such that damage does notoccur through the pixel definition layer or the planarization layerpositioned on the barrier layer, and such that damage does not occurthrough the metal auxiliary layer including the same material as one ofthe gate conductor, the data conductor, and the pixel electrode. Inexemplary embodiments, the emission layer is disconnected in theopening, and is not continuously formed in the pixel area. Accordingly,damage of the light-emitting element positioned in the pixel area due tothe penetration of outside air or moisture through the emission layermay be prevented or reduced.

While the present invention has been particularly shown and describedwith reference to the exemplary embodiments thereof, it will beunderstood by those of ordinary skill in the art that various changes inform and detail may be made therein without departing from the spiritand scope of the present invention as defined by the following claims.

What is claimed is:
 1. A display device, comprising: a substratecomprising a first layer and a second layer; a light-emitting diodedisposed on a display area of the substrate; an organic layer disposedbetween the substrate and the light-emitting diode; an encapsulationlayer disposed on the light-emitting diode, wherein the encapsulationlayer comprises at least one inorganic layer; and an opening disposed inthe display area and penetrating the substrate, wherein the openingcomprises a first protruded portion protruding toward a center of theopening and a first depressed portion, and wherein the first depressedportion is defined by a lower surface, an upper surface opposing thelower surface, and a side surface connecting the lower surface to theupper surface.
 2. The display device of claim 1, wherein the firstprotruded portion and the first depressed portion are disposed in thesubstrate.
 3. The display device of claim 1, wherein the first protrudedportion is disposed in the second layer, and the first depressed portionis disposed in the first layer.
 4. The display device of claim 1,wherein the first layer and the second layer are alternately stacked atleast twice.
 5. The display device of claim 4, wherein the openingcomprises at least one additional protruded portion, and the firstprotruded portion and the at least one additional protruded portion aredifferentiated by a protrusion degree.
 6. The display device of claim 4,wherein a protrusion degree of the first protruded portion and the atleast one additional protruded portion increases as a distance from thelight-emitting diode increases.
 7. The display device of claim 1,wherein an ultraviolet (UV) transmittance of the first layer is lowerthan a UV transmittance of the second layer.
 8. The display device ofclaim 1, wherein the first layer absorbs a greater amount of UV lightthan the second layer.
 9. The display device of claim 1, wherein theorganic layer comprises at least one of a planarization layer and apartition wall.
 10. The display device of claim 9, wherein an end of atleast one of a planarization layer and a partition wall overlaps thefirst protruded portion.
 11. The display device of claim 9, wherein anend of at least one of the planarization layer and the partition wall isaligned with the first protruded portion.
 12. The display device ofclaim 1, wherein the light-emitting diode comprises: a first electrodeconnected to a transistor; a second electrode overlapping the firstelectrode; and an emission layer disposed between the first electrodeand the second electrode, wherein a part of the emission layer overlapsan end of the first protruded portion.
 13. The display device of claim12, wherein the emission layer includes at least one among a holeinjection region, a hole transporting region, an electron injectionregion, and an electron transporting region.
 14. The display device ofclaim 1, wherein the at least one inorganic layer defines the opening.15. The display device of claim 14, wherein the at least one inorganiclayer comprises at least two layers.
 16. The display device of claim 1,wherein the opening further comprises: a second protruded portionprotruding toward the center of the opening; and a second depressedportion disposed below the second protruded portion, wherein the firstdepressed portion is disposed between the first and second protrudedportions, and wherein the first and second protruded portions aredisposed closer to the center of the opening than the first and seconddepressed portions.
 17. The display device of claim 16, wherein thesecond depressed portion, the second protruded portion, the firstdepressed portion, and the first protruded portion are sequentiallyarranged on the substrate in a direction extending away from thesubstrate, and the second protruded portion protrudes further toward thecenter of the opening than the first protruded portion.
 18. A displaydevice, comprising: a substrate comprising a first layer and a secondlayer, and a display area in which an image is displayed; alight-emitting diode disposed in the display area; an encapsulationlayer disposed on the light-emitting diode, wherein the thin filmencapsulation layer comprises at least two inorganic layers; and anopening disposed in the display area and penetrating the substrate,wherein the first layer and the second layer are alternately stacked atleast twice, and a protruded portion is disposed in the second layer anda depressed portion is disposed in the first layer.
 19. The displaydevice of claim 18, wherein the display device comprises at least two ofthe protruded portions, and at least two of the protruded portions aredifferentiated by a protrusion degree.
 20. The display device of claim18, wherein the opening overlaps a module such as a camera or a sensor.21. A display device, comprising: a substrate comprising a first layerand a second layer; a light-emitting diode disposed on a display area ofthe substrate; an organic layer disposed between the substrate and thelight-emitting diode; an encapsulation layer disposed on thelight-emitting diode, wherein the encapsulation layer comprises at leastone inorganic layer; and an opening disposed in the display area andpenetrating the substrate, wherein the opening comprises: a firstprotruded portion protruding toward a center of the opening and a firstdepressed portion; a second protruded portion protruding toward thecenter of the opening; and a second depressed portion disposed below thesecond protruded portion, wherein the first depressed portion isdisposed between the first and second protruded portions, and whereinthe first and second protruded portions are disposed closer to thecenter of the opening than the first and second depressed portions. 22.The display device of claim 21, wherein the second depressed portion,the second protruded portion, the first depressed portion, and the firstprotruded portion are sequentially arranged on the substrate in adirection extending away from the substrate, and the second protrudedportion protrudes further toward the center of the opening than thefirst protruded portion.